Operating mechanism for gun breeches



2 Sheets-Sheet 1 Jn venian:

Nov. 19, 1963 P. zEHFELD ETAL OPERATING MECHANISM FOR GUN BREECHES Filed Jan. 30, 1962 w a a En Piu Z Z e fe ZZ Hel-Zeri' Gramsci off 5y m @e m WJ @n f Nov. 19, 1963 P. zEHFELD Er AL 3,111,061 OPERATING MECHANISM FOR GUN BREECHES Filed Jan. 30, 1962 2 Sheets-Sheet 2 Fly. 2

16 A. :1 :E1- L 19 Z @d United States Patent O OPERATING MECHANISM 'FOR GUN BREECHES Paul Zehfeld, Dusseldorf, and Herbert Grossschopf, Grevenbroich, Lower Rhine, Germany, assignors to Firma Rheinmetall G.m.b.H., Dusseldorf, Germany Filed Jan. 30, 1962, Ser. No. 169,780 Claims priority, application Germany Feb. 6, 1961 Claims. (Cl. 89--24) The invention relates to an operating mechanism for opening and closing the breeches of guns.

The most diverse constructions lare known in this eld.

In the most usual ones, opening of the breech is etected on the iforward movement of the barrel by means of a crank which is set in rotation by a pawl and thereby opens the breech. During this rotation, the closing spring is tensioned by means of a toothed wheel. On loading, the breech is closed by the relaxing closing spr-ing.

This known construction therefore has no opening spring. Its `disadvantage consists in that if the Ibreech is jammed, say by a broken case or the like, the crank cannot turn on striking against the pawl. In that case, either the barrel sticks in this position during the forward movement or, if the speed or energy of the forward movement is too great, the pawl and crank 'are broken.

Since, in this construction, the energy of the forward movement of the barrel must be high in order to open the breech and also tension the closing spring, satisfactory cartridge cases and strong moving elements lare a prerequisite for the working of the operating mechanism. Thus, this construction, which is 'also referred toas a semirigid system, has considerable disadv-antages.

According to another construction, the opening of the breech is effected on the recoil of the barrel, an opening spring `being tensioned until it has suiiicient force to unlock and throw ope-n the breech lblock or closure. Thus, we have here a kin-d of buler. Closing is carried out by means of -a closing spring which is tensioned by the opening breech block.

The drawback of this construction consists in that the breech block is unlocked and opened on recoil of the barrel. This postulates that the cartridge cases have retracted in the barrel in this short time and, moreover, that there must be no more ygas pressure in the barrel. If this is not the case, the breech ca-nnot 'be opened, since the opening force is no longer available when the barrel runs forward. In fact, the opening spring is then relaxed aga-in.

This construction can also only -be employed for short recoils and, even here, is not absolutely reliable in operation, since too many factors, such as condition of the case, gas pressure, etc., are not always the same during tiring.

According t-o a further construction, opening of the breech is effected as the barrel moves forward. In this case, the opening means as such is mounted ixedly on the gun cr-adle, while the closing means is mounted on the breech ring and participates in the movements of the barrel.

In this construction, the closing means of the advancing i barrel `strikes -by means of its tensioning Vbolt against that of the opening means and thereby tensions the opening spring. When the latter has been tensioned to a suicient extent, it is released Vby the tensioning bolt being drawn od and throws the 'breech open, the closing spring being tensioned at the same time. The forward movement of the barrel can only be completed after these movement processes.

This system always requires a satisfactory, steady and complete Iforward movement o-f the ybarrel for any elevation of the latter. The barrel must not lag behind, not even when, for example, the recuperator has been made ice hot by rapid lire. The opening means and closing means must be `adjusted exactly to one another in their operation. Moreover, this construction is very susceptible to trouble through fouling with dust and sand, etc., since it has Ia number o-f spring-loaded pawls and bolts.

The invention avoids the drawbacks of the known constructions dealt with briey above, from which it diiers advantageously above all in that the complete operating mechanism with the tensioning device and locking devices is mounted on the breech Iri-ng of the gun. It participates in all the movements of the barrel, such las recoil, forward movement, elevation, etc. Furthermore, it combines in itself the opening and closing functions. Its principal parts are accommodated in as dust-tight a manner as possible in a cylindrical housing. These parts are mostly simple turned parts. Diflicult milling operations are avoided.

According to an embodiment of the invention, the breech operating mechanism contains a tensioning device actuated mechanically by the recoiling gun barrel for jointly tensioning the Iopening spring and the closing spring. Furthermore, a manually operated tensioning device associated with the closing spring is provided for tensioning said closing -spring when the breech is opened by hand with the gun barrel at rest.

As -a further development rof the invention, two locking devices lare provided, one of which serves to lock the mechanically operated common tensioning device for the two springs in the tensioned condition, when the springs are tensioned, and the other only to lock the tensioned closing spring when the common tensioning device -for the two springs is unlocked `and the opening spring is relaxed Iand the breech is open.

Further details ot the invention will `appear from the following description of the example of embodiment illustrated in the drawing, in which:

FIG. 1 shows the breech ring in side View together with the operating mechanism in longitudinal section:

FIG. 2 is a longitudinal section through that part of the operating mechanism which contains the locking devices, in one position of said locking devices; and

FIG. 3 is a longitudinal section through that part of the operating mechanism which contains the locking devices, in another position of said locking devices.

The operating mechanism consists of a housing 2 mounted on the breech ring 1 Iand in which a so-called pressure rod 3 is mounted to be axially displaceable. This pressure rod is surrounded by a so-called spring tensioning sleeve 4 which is likewise mounted in the housing 2 to be axially Idisplaceable therein. The opening spring 5 and the closing spring 6 are arranged between the two parts 3, 4. The opening spring 5 is disposed completely Within the spring tensioning sleeve 4 and is supported at one of its ends against one end of the spring tensioning sleeve 4. The other end of the spring 5 rests against the annular shoulder 7 of a sleeve 8 mounted :loosely on the pressure rod 3, said sleeve 8 Ibeing supported by the annular shoulder 7 both against the adjacent end of the spring tensioning sleeve 4 and against an annular shoulder 9 on the nressure rod 3.

The closing spring 6 is located within the opening spring S. It is supported at one of its ends against the sleeve 3. Its other end located outside the spring tensioning sleeve 4 rests against the end or base of the housing 2.

The spring tensioning sleeve 4 has on its periphery over a part of its length a toothing l@ with which there meshes a pinion 11 mounted on a shaft, not shown, in an opening 21. Also mounted on the opening shaft is a hand lever, not shown, for opening the breech by hand. Moreover, a locking device in the form of a double locking pawl 12 is associated with the pinion 11.

The pressure rod 3 is connected at one end to a ten- Sioning lever 13 which carries at its free end a roller 14 designed to run onto and olf a cam path 15.

Furthermore, the pressure rod 3 has at its other end two locking notches 16, 17 located one behind the other on its periphery for the locking latch 18 of a locking vlever 19 which is connected to a control pin 20 which is iocated in the path of movement of the spring tensioning 'sleeve 4 and is axially slidable. The locking lever 19 and the control pin Z are mounted in that end of the housing 12 which is remote from the tensioning lever 13.

After firing, owing to the recoil of the barrel the roller 14 of the tensioning lever 13 runs along on the fixed cam path 15, whereby the pressure rod 3 is pushed into the housing 2. 1n this process, it pushes the sleeve 8 in front of it and the latter tensions the opening spring 5 and the closing spring 6', since the spring tensioning sleeve 4 is locked by the locking pawl 12 and the pinion 11, i.e. it cannot move axially, and therefore prevents the opening spring S yielding axially to the left, While the closing spring 6 is supported by the base or end of the housing 2. Thus, both springs, i.e. the opening spring 5 and the closing spring 6, are mechanically tensioned together. The tensioning travel is about 50 mm. As the pinion 11 is locked by the locking pawl 12 during the movements of the barrel, both on recoil and on forward movement, the spring tensioning sleeve 4 remains in the inoperative position.

The pressure rod 3 is shifted so far to the left by the running of the roller 14 onto the cam path 15 that the latch 18 of the latch lever 19 moves out of the notch 17 into the notch 16. The pressure rod 3 is thereby locked with the springs 5, 6 tensioned. This tensioned position 1s also maintained when the roller 14 of the tensioning lever lhas left the cam path again on forward movement of the barrel. In this way independence of the operating mechanism of the position and length of the cam path 15 is obtained.

When the gun barrel has reached the end of its recoil, the forward movement begins, the locking pawl 12 being swung out of the position shown in FIGS. l and 2 into the neutral position and releasing the pinion 11. The opening spring can now relax and in so doing urges the spring tensioning sleeve 4 to the left, said sleeve rotating by 'way of the pinion 11 a shaft, not shown, in the opening 21 which swings the breech block of the gun into the open position.

During the movement of the spring tensioning sleeve d to the left the sleeve strikes against the control pin 'and shifts it to the left. In this process the control pin 29 swings the locking lever 19 clockwise, whereby the locking latch 1S is disengaged from the notch 16. Nevert'neless, the closing spring 6 cannot yet, relax, however, since the locking pawl 12 has meanwhile been swung out of its neutral position into the position shown in FIG. 3. Hence, the locking pawl prevents by way of the pinion 11 any movement of the spring tensioning sleeve 4 to the right. However, as the closing spring 6 rests against the sleeve 8 and the latter rests against the adjacent end of the spring tensioning sleeve 4, the closing spring 6 is still blocked in the tensioned position.

Only when the locking pawl 12 is brought out of the position shown in FlG. 3 into the neutral position, in which it releases the pinion 11, can the closing spring 6 relax, since it can now push the spring tensioning sleeve 4 and the pressure rod 3 to the right by way of the sleeve 8.

Control of the locking pawl 12 is effected by means of ixed stops (not shown) which are mounted on parts of the gun which are not moved, such as, for example, the carriage of mounting, the cradle or the like. By a suit- .able position of the stops, it is possible, according to the type of gun, so to control the opening and closing springs that the breech is opened ,ata very denite time and is set .up for closing.

If the breech is to be opened by hand with the gun barrel at rest, the locking pawl 12 is brought out of engagement with the pinion 11. A hand crank (not shown) mounted on the opening shaft is thereupon turned, for example to the right, whereby the pinion 11 is set in rotation and shifts the spring tensioning sleeve 4 to the left, the latter tensioning the closing spring 6 in this process in that it carries the sleeve 8 along to the left on the pressure rod 3. The opening spring 5 lies untensioned between the sleeve S and the opposite end of the spring tensioning sleeve 4.

According to the invention, both springs 5, 6 are tensicned mechanically in the direction of movement by the recoil of the gun barrel, so as then to relax each by itself in opposite directions and in so doing perform their functions. Moreover, only the closing spring 6 can be tensioned with the barrel at rest when the breech is opened by hand.

VJ hat we claim is:

l. Operating mechanism for the breech ring of gun barrels comprising a housing mounted on the breech ring, a spring tensioning sleeve mounted for axial displacement in the housing, a pressure rod mounted for axial displacement in the housing, a sleeve loosely mounted on the pressure rod and having an annular shoulder on one end thereof, an opening spring mounted in the tensioning sleeve bearing at one end against the tensioning sleeve and the other end against the annular shoulder of the second-mentioned sleeve, a closing spring around the pressure rod bearing at one end against the housing and the other end against the second-mentioned sleeve, and means operated by the breech ring and connected to the pressure rod to slidably actuate the latter upon recoil of the gun barrel to jointly tension the opening and closing springs.

2. Operating mechanism according to claim l, in which a pinion is provided extending through the housing and said tensioning sleeve has a plurality of teeth on a part of its length with the pinion meshing with the teeth to manually actuate the spring tensioning sleeve relative to the second-mentioned sleeve.

3. Operating mechanism according to claim l, in which a pinion is provided extending through the housing and said tensioning sleeve has a plurality of teeth on Ia part of its length with the pinion meshing tvit-h the teeth to manually :actuate the spring tensioning sleeve relative to the second-mentioned sleeve, and in which a locking device is provided consisting of a double locking pawl to engage in the pinio-n.

4. Operating mechanism according to claim l, in which a pinion is provided extending through the housing and said tensioning sleeve has a plurality of teeth on a part of its length with the pinion meshing with the teeth to manually actuate the spring tensioning sleeve relative to the second-mentioned sleeve, and in which la locking device is provided consisting of a double locking pawl to engage in the pinion, during the movement of the gun barrel and the spring tensioning sleeve whereby the pinion will be locked by the double locking pawl.

5. Operating mechanismy according to claim l, in which the pressure rod and the spring tensioning sleeve are displaceable lboth together and in relation to one another, and in which second-mentioned sleeve is mounted loosely on the pressure rod.

6. Operating mechanism according to cl-aim l, in which the opening spring which rests at one end against the annular shoulder of the spring tensioning sleeve rests at its other end against an annular shoulder on .the secondmentioned sleeve mounted loosely on the pressure rod.

References Cited in the file of this patent UNITED STATES PATENTS 2,434,972 vic-k 1an. 27, 194s 

1. OPERATING MECHANISM FOR THE BREECH RING OF GUN BARRELS COMPRISING A HOUSING MOUNTED ON THE BREECH RING, A SPRING TENSIONING SLEEVE MOUNTED FOR AXIAL DISPLACEMENT IN THE HOUSING, A PRESSURE ROD MOUNTED FOR AXIAL DISPLACEMENT IN THE HOUSING, A SLEEVE LOOSELY MOUNTED ON THE PRESSURE ROD AND HAVING AN ANNULAR SHOULDER ON ONE END THEREOF, AN OPENING SPRING MOUNTED IN THE TENSIONING SLEEVE BEARING AT ONE END AGAINST THE TENSIONING SLEEVE AND THE OTHER END AGAINST THE ANNULAR SHOULDER OF THE SECOND-MENTIONED SLEEVE, A CLOSING SPRING AROUND THE PRESSURE ROD BEARING AT ONE END AGAINST THE HOUSING AND 